Disruption of the Body Temperature Circadian Rhythm in Hospitalized Patients

The circadian rhythm of human body temperature - Clinical implications and review of the literature

Human body temperature remains an essential vital sign that had been used to judge our health given its strong correlation with human disease. Body temperature is also a manifestation of our circadian rhythm, with a predictable rise during the day peaking in the evenings and steady decrease during the night reaching a minimum around the time of awakening. Yet, the rhythm is believed to be endogenous and to exist independently of any external stimuli, including day light. Human illnesses such as infections, autoimmune conditions, and cancer had been associated with a disruption in the circadian rhythm. This is of significant clinical interest because measurements of the specific disruptions of the rhythm appear to carry diagnostic and prognostic value. This is a review of the literature with a focus on the determinants of human body temperature and the circadian rhythm of body temperature. The last section provides potential new research avenues in our search for chronotherapy clinical applications.

Accurate diagnosis and effective treatment of abnormal meridians in erectile dysfunction patients based on infrared thermography: an electrophysiological technique study

An increasing body of research has demonstrated that appropriate stimulation of the meridians and acupoints in the human body can play a preventative and therapeutic role in diseases. This study combines the use of infrared thermography with intelligent electrophysiological diagnostic system (iEDS) to accurately diagnose and apply transdermal low-frequency electrical stimulation to treat abnormal meridians in patients with erectile dysfunction (ED). The treatment protocol included 6 treatments (each lasting 30 min and performed twice a week). The International Index of Erectile Function-5 (IIEF-5), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Erection Hardness Scale were used to assess treatment results. A total of 62 patients were included in this study, with 31 patients in the treatment group and 31 patients in the sham therapy group. After six treatments, the treatment group improved significantly in IIEF-5 (15.52 ± 2.06 vs. 18.84 ± 2.67, p < 0.001), PHQ-9 (8.32 ± 6.33 vs. 4.87 ± 4.41, p < 0.001), GAD-7 (5.32 ± 5.08 vs. 2.94 ± 3.31, p = 0.003), and EHS (2.48 (2.00, 3.00) vs. 2.90 (2.00, 3.00), p = 0.007). After six sham treatment sessions, no improvements in any of the scores were reported in the sham therapy group. Following that, this group had an additional six treatments of regular therapy, which resulted in statistically significant improvements in IIEF-5 (16.65 ± 1.96 VS. 19.16 ± 2.40, p < 0.001), PHQ-9 (8.81 ± 6.25 VS. 4.97 ± 4.36, p < 0.001), GAD-7 (5.74 ± 5.18 VS. 3.68 ± 3.42, p < 0.001), and EHS (2.61 (2.00, 3.00) VS. 3.03 (2.00, 4.00), p = 0.003). No adverse events were reported regarding penile discomfort, pain, injury, or deformity. CLINICAL TRIALS: The study protocol is registered in the Clinical Trials Registry with the identification number ChiCTR2300070262.

Personalized Cutoffs for the Diagnosis of Neutropenic Fever Based on Patients' Baseline Body Temperature: A Retrospective Pilot Study

Background The management of neutropenic fever patients remains challenging. Patients' individual baseline body temperature may provide diagnostic and prognostic value. Methods This study is a retrospective analysis of 92 adults admitted for neutropenic fever to model the length of stay (LOS) and the ability to find a definitive diagnosis using the deviation of patients' temperature on admission from their outpatient baseline, acuity on admission, neutropenia level and persistence, fever persistence, and patients' age. Results Patients' average baseline body temperature was 36.7°C+/-0.3°C - the body temperature had to be over four standard deviations above the baseline to reach the gold standard fever threshold of 38.0°C. Their average fever on admission was 38.1°C. Fever etiologies were identified in 48%, and all constituted infections. Multiple regression modelling demonstrated that a longer LOS of >3 days was predicted by larger deviation from baseline body temperature at admission and by fever persistence at 72 hours post-admission, after correcting for the persistence of severe neutropenia (absolute neutrophil count <500) at 72 hours, age, neutropenia level, and need for intensive care unit admission. A similar model could not predict the ability to identify a fever-explaining diagnosis. Conclusions This pilot project provides support for the use of patients' individual baseline body temperature rather than a pre-established universal fever cutoff in the diagnosis of neutropenic fever. Using a personalized cutoff is expected to avoid missing cases. Further, deviation from patients' baseline body temperature at admission could serve as a predictor for the hospital LOS, which can serve as a potential tool for hospital bed management.

Temperature control after cardiac arrest

Managing temperature is an important part of post-cardiac arrest care. Fever or hyperthermia during the first few days after cardiac arrest is associated with worse outcomes in many studies. Clinical data have not determined any target temperature or duration of temperature management that clearly improves patient outcomes. Current guidelines and recent reviews recommend controlling temperature to prevent hyperthermia. Higher temperatures can lead to secondary brain injury by increasing seizures, brain edema and metabolic demand. Some data suggest that targeting temperature below normal could benefit select patients where this pathology is common. Clinical temperature management should address the physiology of heat balance. Core temperature reflects the heat content of the head and torso, and changes in core temperature result from changes in the balance of heat production and heat loss. Clinical management of patients after cardiac arrest should include measurement of core temperature at accurate sites and monitoring signs of heat production including shivering. Multiple methods can increase or decrease heat loss, including external and internal devices. Heat loss can trigger compensatory reflexes that increase stress and metabolic demand. Therefore, any active temperature management should include specific pharmacotherapy or other interventions to control thermogenesis, especially shivering. More research is required to determine whether individualized temperature management can improve outcomes.

Effect of Circadian Rhythm Disturbance on the Human Musculoskeletal System and the Importance of Nutritional Strategies

The circadian system in the human body responds to daily environmental changes to optimise behaviour according to the biological clock and also influences various physiological processes. The suprachiasmatic nuclei are located in the anterior hypothalamus of the brain, and they synchronise to the 24 h light/dark cycle. Human physiological functions are highly dependent on the regulation of the internal circadian clock. Skeletal muscles comprise the largest collection of peripheral clocks in the human body. Both central and peripheral clocks regulate the interaction between the musculoskeletal system and energy metabolism. The skeletal muscle circadian clock plays a vital role in lipid and glucose metabolism. The pathogenesis of osteoporosis is related to an alteration in the circadian rhythm. In the present review, we discuss the disturbance of the circadian rhythm and its resultant effect on the musculoskeletal system. We also discuss the nutritional strategies that are potentially effective in maintaining the system's homeostasis. Active collaborations between nutritionists and physiologists in the field of chronobiological and chrononutrition will further clarify these interactions. This review may be necessary for successful interventions in reducing morbidity and mortality resulting from musculoskeletal disturbances.

Optimal diagnostic fever thresholds using non-contact infrared thermometers under COVID-19

Fever screening is an effective method to detect infectors associated with different variants of coronavirus disease 2019 (COVID-19) based on the fact that most infectors with COVID-19 have fever symptoms. Non-contact infrared thermometers (NCITs) are widely used in fever screening. Nevertheless, authoritative data is lacking in defining "fever" at different body surface sites when using NCITs. The purpose of this study was to determine the optimal diagnostic threshold for fever screening using NICTs at different body surface sites, to improve the accuracy of fever screening and provide theoretical reference for healthcare policy. Participants (n = 1860) who were outpatients or emergency patients at Chengdu Women's and Children's Central Hospital were recruited for this prospective investigation from March 1 to June 30, 2021. NCITs and mercury axillary thermometers were used to measure neck, temple, forehead and wrist temperatures of all participants. Receiver operating characteristic curves were used to reflect the accuracy of NCITs. Linear correlation analysis was used to show the effect of age on body temperature. Multilinear regression analysis was used to explore the association between non-febrile participant's covariates and neck temperature. The mean age of participants was 3.45 ± 2.85 years for children and 28.56 ± 7.25 years for adults. In addition 1,304 (70.1%) participants were children (≤12), and 683 (36.7%) were male. The neck temperature exhibited the highest accuracy among the four sites. Further the optimal fever diagnostic thresholds of NCITs at the four body surface measurement sites were neck (36.75 °C, sensitivity: 0.993, specificity: 0.858); temple (36.55 °C, sensitivity: 0.974, specificity: 0.874); forehead (36.45 °C, sensitivity: 0.961, specificity: 0.813); and wrist (36.15 °C, sensitivity: 0.951, specificity: 0.434). Based on the findings of our study, we recommend 36.15, 36.45, 36.55, and 36.75 °C as the diagnostic thresholds of fever at the wrist, forehead, temple and neck, respectively. Among the four surface sites, neck temperature exhibited the highest accuracy.